JPH05272884A - Regenerative heat exchanger - Google Patents

Abstract

PURPOSE:To raise heat exchanging temp. by a method wherein a weight support is provided at the inner peripheral surface of a cylindrical outer wall and regenerative bodies are built up in layers above the weight support with the lowest regenerative body shaped into the form of an arch. CONSTITUTION:The lower part of regenerative bodies 1 is shaped into the form of an arch and a metal-made suppor 9 for supporting the weight of the regenerative bodies is provided at the outer periphery of the lower part of a heat exchanger. A heating gas is sent through the small holes formed in the regenerative bodies 1 to impart heat thereto and an unheated gas is then sent therethrough to absorb heat from the regenerative bodies 1. When the heating gas is passing through the regenerative bodies 1, the temp. distributed to the outer peripheral part of the regenerative bodies 1 is lower than that distributed to the central part thereof. The metal-made support 9 provided at the outer periphery of the regenerative body 1 having the low temp. is sufficient to support the total weight thereof. The metal supporting structure thus arranged at the part of the regenerative body having the lowest temp. can increase the temp. of the regenerative body itself and the heat exchanging temp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat storage type heat exchanger used in MHD power generators and the like.

[0002]

2. Description of the Related Art Generally, for heat exchange of a high temperature gas that exceeds the heat resistant temperature of a metal, a heat storage type heat exchanger that transfers heat via a ceramic heat storage body is used. In the heat storage type heat exchanger, the heat storage gas is heated by the heating gas, and the heated gas passes through the heated heat storage body to heat the heating target gas.

As this heat storage body, as shown in FIG. 3, a brick-shaped heat storage body (cored brick) (1) provided with a large number of through holes (1 ') is used. At this time,
Even when the heat storage bodies (1) are stacked, the pores penetrate from the upper part to the lower part at the same position. The heating gas flows from the upper part to the lower part inside the heat storage type heat exchanger, and the heated gas flows from the lower part to the upper part. In this heat storage type heat exchanger, the amount of heat exchanged is uniquely determined by the product of the specific heat and the weight of the heat storage body (1), so if it is a large capacity heat exchanger, the weight of the heat storage body alone will be several thousand kg or more. .. For this reason, in order to support this weight, a metal load receiver (9 ') is used in the lowermost part of the heat exchanger to have high strength and to secure a passage for heating gas and heated gas.

[0004]

The load receiver (9 ') of the heat storage body is made of a metallic material in terms of strength. However, the strength of the metal depends on the temperature, which makes it difficult to use at high temperatures. For example, even in cast stainless steel, the operating temperature limit is about 800 ° C. Therefore, in the conventional heat storage type heat exchanger, the temperature at the bottom of the heat storage body must be 800 ° C or lower.

For this reason, the higher the heat exchange temperature, that is, the higher the temperature of the top of the heat storage body, the higher the height of the heat storage body, and the lower the temperature rise at the bottom due to the thermal gradient. It was necessary and the heat exchange temperature could not be raised sufficiently. An object of the present invention is to realize a heat storage type heat exchanger capable of taking a sufficiently high heat exchange temperature.

[0006]

According to the present invention, a load receiver is provided on the inner peripheral surface of a cylindrical outer shell, and a heat storage body is laminated on the load bearing with the lower portion arched.

[0007]

[Operation] By making the lower part of the laminated heat storage body arcuate, the total weight of the heat storage body is applied to the outer peripheral portion through the arch portion, so that if the outer peripheral portion is supported, the total weight of the heat storage body will be retained. It will be possible. Further, the heat storage body has a temperature gradient in the radial direction from the center to the outside because the outside is the normal temperature atmosphere inside the heat exchanger. Therefore, the outermost peripheral portion, which is the heat storage body holding portion, has the lowest temperature in the heat storage body. By providing the metal support structure in such a portion, the attainable temperature of the lower center of the heat storage body is increased as compared with the metal holding structure in the conventional technique.

[0008]

FIG. 1 shows an embodiment of the present invention. In FIG. 1, (3) is an outer shell of the heat storage type heat exchanger, and a heat resistant brick (2) is stuck inside the outer shell. In the upper part, the heating gas inlet (5), the bypass (6) and the heated gas outlet (4) are provided.
A heating gas outlet (8) and a heated gas inlet (7) are provided in the lower part. A heat storage body (cored brick) (1) with a large number of pores is stacked inside, and the lower part of the heat storage body (1) is formed in an arch shape, and a metal-made outer peripheral portion of the lower part of the heat exchanger is formed. The load receiver (9) of the heat storage body is arranged. As the material of the heat storage body (1), oxide ceramics such as zirconia and alumina are used.

The heating gas gives heat to the heat storage body through the pores formed in the heat storage body (1), and then the gas to be heated passes through the pores and absorbs the heat from the heat storage body. The temperature of the heat storage body heated by the heating gas passing through the heat storage body has a distribution in which the temperature of the outer peripheral portion is lower than that of the central portion. By arranging a load receiver (9) made of metal on the outer peripheral portion as shown in FIG. 1, the total weight of the heat storage body can be held at the low temperature portion.

With such a structure and action, a metal holding structure can be provided in the lowest temperature portion of the heat storage body, whereby the temperature of the heat storage body itself can be raised and the heat exchange temperature can be raised. (Other embodiments)

(1) As shown in FIG. 1, the load receiver (9) of the heat storage body is provided with a cooling water passage (11) to forcibly cool the load receiver (9). By doing so, the temperature of the load receiver (9) can be cooled from the inside, and the strength can be secured. This makes it possible to raise the temperature of the heat storage body and further raise the heat exchange temperature.

(2) As shown in FIG. 2, the lowermost part of the cored brick type heat storage body (1) is formed into an arch shape, and a plurality of spherical heat storage bodies (10) (called pebble) are stacked on the arched shape. In this heat exchanger, it is not necessary to orderly stack the cored brick type heat storage bodies, so that the manufacturing time can be shortened.

[0013]

In the heat exchanger of the present invention, the weight of the heat storage body can be supported by the lowest temperature portion due to the temperature gradient in the radial direction inside the heat storage body, and when the heat exchanger exchange temperature has the same specifications. As for the material of the holding portion, it is possible to use one having a low strength, and if it is a high quality material, the safety thereof can be enhanced. Further, if the temperature of the holding portion is kept constant, the absolute temperature of the central portion of the heat storage body can be increased, and the performance of the heat exchanger itself can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a heat storage type heat exchanger of the present invention.

FIG. 2 is a diagram showing another embodiment according to the present invention.

FIG. 3 is a sectional view of a conventional heat storage type heat exchanger.

[Explanation of symbols]

 1 ... Heat storage body (cored brick) 1 '... Pore 2 ... Heat resistant brick 3 ... Outer shell 4 ... Heated gas outlet 5 ... Heating gas inlet 6 ... Bypass 7 ... Heated gas inlet 8 ... Heating gas outlet 9, 9 ′… Load receiver 10… Heat storage body (pebble) 11… Cooling channel

Claims (1)

[Claims] 1. A heat storage type heat exchanger characterized in that a load receiver is provided on an inner peripheral surface of a tubular outer shell, and a heat storage body is laminated on the load receiver with a lower portion having an arch shape.